Michell EA2-TX-100

Core Technical Specifications

1. Moisture Measurement Performance Parameters
   • Dew Point Measurement Range: -100°C ~ +20°C dew point full scale, user configurable custom output sub-range
   • Alternative Output Unit: Gas moisture content 0 ~ 3000 ppmV water vapor
   • Measurement Accuracy: ±2°C dew point full range precision
   • Repeatability Error: ≤0.5°C dew point
   • Response Speed: T63 1 minute (dry to wet gas condition), T95 5 minutes (wet to dry gas recovery)
   • Temperature Compensation: Built-in integrated temperature sensor full-range automatic temperature drift correction
2. Electrical Loop Power Parameters
   • 2-Wire Loop Supply Voltage: 12 VDC ~ 28 VDC wide range power supply
   • Maximum Loop Current Consumption: 20 mA full scale analog output
   • Maximum Load Resistance: 500 Ω under 24 VDC supply, 250 Ω under 12 VDC supply
   • Diagnostic Current Signals: Under-range 3.6 mA, over-range 21 mA, sensor fault 2.4 mA standard fault coding
3. Mechanical & Process Parameters
   • Process Connection Thread: 5/8” – 18 UNF standard gas pipeline thread
   • Process Working Pressure: Maximum 45 MPa (450 barg) high pressure gas measurement support
   • Recommended Gas Flow Rate: 1 ~ 5 NL/min in sampling block installation; 0 ~ 10 m/s flow velocity direct insertion
   • Operating Ambient Temperature: -40°C ~ +60°C transmitter body temperature range
   • Protection Rating: IP66 / NEMA 4 ingress protection for transmitter housing
   • Net Weight: 150 g compact lightweight design

Function Features

• Working Principle: Proprietary ceramic capacitive sensing element forms variable capacitance proportional to gas water vapor partial pressure; internal signal conditioning circuit converts capacitance value to dew point temperature value via built-in calibration algorithm; 2-wire loop-powered circuit modulates total loop current between 4–20 mA corresponding to full dew point measurement range, without separate auxiliary power supply for field installation
• Long-term stable ceramic sensor core, minimal zero drift compared to aluminum oxide competitive sensors, no frequent annual recalibration requirement
• Compact probe design supporting direct insertion into gas pipeline or installation in external sampling flow block
• Factory traceable calibration to UK NPL and US NIST national measurement laboratories
• Built-in sensor self-diagnosis logic, output fixed fault current value when sensor damage or gas over-range occurs for remote system fault identification
• Stainless steel corrosion-resistant probe body compatible with inert industrial gases, low-concentration non-oxidizing acid gas environments
• Wide pressure tolerance suitable for high-pressure industrial nitrogen, oxygen, compressed air pipeline monitoring

Material Composition

• Transmitter Main Housing: Machined 316L stainless steel solid bar anti-corrosion body
• Sensing Core Protective Sleeve: High-density HDPE porous protective filter sleeve, filter particle impurities in gas flow
• Internal Circuit Enclosure: Sealed PBT plastic electronic compartment with silicone sealing ring
• Electrical Connection Plug: Hirschmann GDS series industrial DIN 4350-C waterproof M12 connector
• Sensing Capacitive Substrate: High-purity aluminum oxide ceramic substrate with proprietary moisture-sensitive polymer coating

Structural Characteristics

• Split two-section structure: front stainless steel measurement probe, rear electronic signal conversion housing
• Central external 5/8” UNF male thread for direct screwing into gas pipeline sampling port
• Rear M12 circular waterproof plug for 2-wire signal power cable connection, easy field wiring replacement
• Porous HDPE filter sleeve covers sensor tip to prevent pipeline dust, oil mist particles from contaminating sensitive ceramic core
• Fully sealed internal electronic compartment to avoid condensation water damage to circuit board in cold gas pipeline environments
• Cylindrical compact shape, no protruding parts, suitable for narrow pipeline installation space

Application Scenarios

• Factory workshop compressed air dryer online dew point monitoring
• Semiconductor manufacturing ultra-dry nitrogen pipeline moisture detection
• Pharmaceutical clean room inert protective gas dryness monitoring
• Food packaging nitrogen blanketing gas moisture content measurement
• Laser cutting machine high-pressure dry air supply pipeline monitoring
• Data center precision air conditioning dry gas system dew point tracking

Installation Requirements

1. Install sampling port at horizontal pipeline upper half position to avoid liquid condensate flowing onto sensor probe
2. Control gas flow rate strictly within 1–5 NL/min when using sampling block; excessive flow causes measurement temperature deviation
3. 2-wire cable maximum transmission distance 1000 m with 1.5 mm² copper twisted pair cable
4. M12 connector sealing ring must be intact during wiring to maintain IP66 waterproof performance
5. Avoid direct probe contact with liquid water, oil or solid particle contaminants in gas pipeline
6. Ambient temperature of transmitter rear electronic housing cannot exceed +60°C; install heat insulation gasket near high-temperature pipeline

   Operation & Maintenance Precautions

   1. If sensor tip is contaminated by oil mist, replace HDPE protective sleeve and perform field calibration
   2. Recommended recalibration cycle every 18 months under normal clean gas operating conditions; shorten to 6 months for oil-containing compressed air
   3. Do not disassemble stainless steel probe body; internal ceramic sensor core cannot be manually replaced on site
   4. Prevent rapid large temperature fluctuation of measured gas; sudden temperature shock accelerates sensor drift
      5. Do not apply mechanical impact or bending force to the slender sensing probe; internal ceramic capacitive chip will crack and lose measurement capability permanently
      6. For pipelines carrying oil-laden compressed air, add an upstream coalescing oil filter to reduce sensor contamination speed
      7. Store the transmitter in a dry nitrogen-sealed storage container during long-term shutdown periods to prevent sensor surface adsorption of ambient moisture
      8. When conducting field calibration, use certified traceable dew point standard gas source to ensure measurement accuracy meets factory specification limits

      Standard Supporting Accessories

      • 5/8” UNF stainless steel sampling tee for pipeline tapping installation
      • HDPE spare filter sleeves (pack of 10) for regular replacement
      • M12 4-pin shielded 2-wire extension cable with IP66 waterproof joint
      • Portable dew point calibration gas kit for on-site verification